This Dinosaur Probably Chirped Like a Bird

Scientists have discovered a dinosaur that might have chirped like a bird, a finding that suggests the evolutionary origins of birdsong may be far more ancient than we previously thought.

In a paper published last week in the journal PeerJ, an international team of researchers describes a 163-million-year-old fossil found in northeastern China’s Hebei Province. The fossil dinosaur, which they’ve dubbed Pulaosaurus qinglong, measures just 28 inches (72 centimeters) and is largely complete, giving researchers an unusually detailed look at its anatomy, including its surprisingly birdlike throat.

“Even when you have a dinosaur skeleton preserved, you don’t always have these isolated bones preserved with other skull elements,” Xing Xu, a paleontologist at the Chinese Academy of Sciences in Beijing and an author of the paper, told The New York Times. “They’re very thin bones, very delicate and hard to preserve.”

In vertebrates, the vocal organs protect the airway and can produce sounds, including basic noises like hisses, groans, and grunts. In most living reptiles, these structures are made of cartilage and are relatively simple. Birds, however, have delicate, bony, flexible vocal organs that can make more complicated and diverse sounds.

Pulaosuarus’ throat seems somewhere between the two. Its vocal structures appear to be similar to that of another dinosaur, Pinacosaurus, a kind of ankylosaur with a large, bony larynx that may have been flexible enough to produce birdlike chirps and tweets, the researchers told the Times.

The researchers believe that Pulaosaurus lived during the late Jurassic period and belonged to the same group of creatures that would later give rise to “duck-billed” dinosaurs like hadrosaurs. But Pulaosaurus and Pinacosaurus are separated by millions of years of evolution, and neither belong to the group of dinosaurs that eventually produced birds. While it’s possible they developed their vocal features independently, the presence of similar structures in such distinct species indicates that dinosaurs’ ancient ancestors may have been pretty chirpy.

That means the origins of birdsong could lie in creatures that lived more than 230 million years ago, but it remains a mystery as to how or when modern birds’ voice box, called the syrinx, evolved—or if any dinosaur shared their incredible vocal prowess.